A typical beta-adrenoceptors are known to occur in adipose tissue and the gastrointestinal tract. A typical beta-adrenoceptor agonists have been found to be particularly useful as thermogenic anti-obesity agents and as anti-diabetic agents. Compounds having a typical beta-adrenoceptor agonist activity have also been described as being useful in the treatment of hyperglycaemia, as animal growth promoters, as blood platelet aggregation inhibitors, as positive inotropic agents and as antiatherosclerotic agents, and as being useful in the treatment of glaucoma.
Compounds which are agonists at atypical beta-adrenoceptors are described, for example, in WO 97/21665, WO 97/21666, WO 98/43953, WO 99/65877, WO 95/33724, EP 0455006 and EP 0543662.